The lamp as long as they work was clearly a good product. I am disappointed by the service life of the whole product, now that the LED is defective in its third year. The light from me was used regularly, approx 5-10 hours per week (during the winter months). Now I realized that the lamp is defective. After a short check of all causes, I came together with the Sigma Service to the conclusion that the LED must be defective. Another error could be excluded because the control LED illuminated. After perhaps 600-1000 hours burn time which is totally unacceptable (I'm actually of more than 10,000 hours out).
A call to the Sigma-Service also brought no success: an exchange of LED is not technically provided. An offer, a new lamp discounted purchase is not made.
My Conclusion: 1. It is a non-sustainable product, I can not only dispose of the lamp but also the charging adapter now if I opt for another model. 2. The manufacturer has little accomodating reacts and is therefore sanctioned the future from me.
